I 2nd Kriston's vote. You 2 are WAY ahead of the game! Just take it 1 day at a time. And I know this has been said before on this board, but it really seems to think best in 6 month segments of time. Even schools themselves can change a lot in 2-3 years.

And siblings make great peer playmates! DS7 and DD3.5 are great together (most of the time anyway). They really "get" each other. When #2 was born, it was definitely time for DS to no longer be the "center of the universe".